The present invention relates to a telecommunications network for mobile users, said telecommunications network for mobile users comprising a user's subsystem and a transport subsystem connected by means of an access subsystem, which offers them respectively a user access communications interface and a transport access communications interface, suitable to permit the exchange of the information flows among said subsystems, said access subsystem identifying a coverage area of the cellular telephone network, through the composition of elementary coverage areas called cells, each one generated by a radio base station that ensures the birectional communication among user subsystems and access subsystem.
Based on various analyses, it is expected that in a short time we will see a large increase in the quantity of information exchanged between users equipped with mobile radiotelephone terminals and the networks of the providers of such services.
In light of such future needs, various national and international organizations (e.g. ITU, ETSI, FCC, etc.) dealing with regulations affecting radio frequencies allocation and utilization and the relative standards of data processing and signal modulation techniques, agreed on the definition of standards (or a group of standards like the IMT 2000) which allows a significant increase in the velocity of exchange of data between the mobile networks and the user mobile terminal and vice versa. The IMT 2000 group of standards, for example, includes the new standards called CDMA 2000 and Universal Mobile Telecommunications System (UMTS) or 3G (third generation) that allow video-conferencing and compatibility with the protocols of Internet networks (e.g., Ipv6) with other networks of the same family (e.g., DECT), and with the previous generation (2G) wireless telephone networks (e.g., GSM and PCS) and their improved data transport versions such as GPRS, EDGE, etc., (usually referred to as 2.5G).
At the same time, methodologies and standards are continuously developed and perfected for the treatment of signals able to minimize the bandwidth requirements for digital transmissions of audio and video signals permitting the efficient transport of music, voice and images on digital networks such as Internet, Intranet and the like.
There is, therefore, reason to believe that the diffusion of new terminals capable of efficient connection to the Internet, to watch videos and to reproduce data, voice, music and television files downloadable from the Internet will bring significant growth in the quantity of data carried by the terrestrial radio networks for the next generation of mobile phones. For example, the third generation cellular systems, using the UMTS standard, are designed for multimedia communications. These person-to-person communications can be improved with quality images and/or video and access to information or services on the private or public networks can benefit from the high available data rate and from the increased communication flexibility of such systems.
These systems offer the following characteristics:                variable bit rate to furnish bandwidth compatible with the service needed (from 16 kbps for voice to 2 Mbps for “High Multimedia”);        multiplexing services with different quality requirements in a single connection;        delay requirements for real time traffic;        quality requirements from 10% frame error to 10−6 bit error rate;        compatibility with 2G systems (e.g., GSM) and handover intersystems for better coverage and traffic balance;        high efficiency in spectrum utilization        compatibility of Frequency Division Duplex (FDD) and Time Division Duplex (TDD) connection modes        support of asymmetric traffic for uplinks (from user to provider) and downlinks (from provider to user).        
Among the most important characteristics of the network based on the UMTS standard are the increased bit rate for the user, compatibility with Internet standards, the ability to run multimedia files and the ability of connecting to the terminal in an “always on” mode.
It is also logical to envision that in the beginning the use of the UMTS network will be primarily made of voice and Internet traffic and that the rate of multimedia traffic will increase over time.
Since the requested information will frequently be available through the Internet, it is important to provide efficient management of TCP/UDP/IP traffic on the UMTS network. In order to be successful, the UMTS network must be able to support a wide array of applications from different requirements for performance and quality of service.
Further, there are technologies in rapid and constant development, which compete in the production of portable radio terminal (user terminals), which are able to incorporate functions beyond basic telephones services, such as the various additional complex functions. These include graphic visualization with good resolution, typical functions of Personal Computers, capability to interpret and process various standards and protocols of the Internet, storage of large quantities of data, elaboration and reproduction of audio and video files based on various standards, ability to run serial interfaces via cable to infrared and radio for data exchange over short distances with other digital units, reception and elaboration of GPS signals, execution of complex interactive games, quick execution of cryptographic codes and voice recognition and synthesis, etc.
All of these capabilities of the user terminal necessary to support the vast array of services foreseen by the 3G mobile telecommunications networks will result in a notable increase in energy consumption. This increase in energy consumption over and above today's 2G terminals (primarily for telephones) will make even more important methodologies aimed at optimizing energy consumption.
Thus, to furnish a service qualitatively acceptable to customers, the wireless network providers will be forced to continuously upgrade their capacity to meet increased demand. If the demand for new mobile network services continues, problems can surface with regard to capacity both on the transport networks and the access networks. To augment the transport capacity, it will be necessary to increase the capacity of various connections, which are theoretically limited only by cost. The access capacity is limited instead by the finite frequency band assigned to each provider. Reducing the dimensions of the coverage cells and thus increasing their numbers can manage the increases in capacity, but this solution presents technical problems if pushed to the extreme and is an endeavor that has its limits.
The UMTS network consists of, at the network architecture level, an assembly of network elements, each with a specific function. At the level of standards, both the logical elements and the open interfaces are defined in a way that makes automatically possible to pick out the physical elements of the network as well.
The presence of open interfaces, in particular in the UMTS Terrestrial Radio Access Network (UTRAN), allows interconnections to the UMTS network in ways not explicitly foreseen by the current standards.
Documentation of the detailed description of services and standardized performance (or those currently being defined) for the 2.5G and 3G mobile telecommunications networks has been produced by the Third Generation Partnership Project (3GPP) and the Third Generation Partnership Project 2 (3GPP2). A synthesis of this information is available in publications such as, “WCDMA for UMTS” by Holma and Toskala, 2000, John Wiley & Sons, while FIG. 1, described below, shows some of the UMTS network elements necessary to describe the invention.
FIG. 1 represents a block diagram at the highest architectural level of a telecommunications network for mobile phone users UNET of the type noted in the UMTS standard. It comprises three subsystems all interconnected as follows:                user terminal subsystem STU that is indicated in the standard as “User Equipment”. This subsystem makes up the user terminal system, i.e. the portable terminal, such as for example, a cellular phone. This user terminal subsystem is interconnected to the telecommunications network for mobile phone users UNET, in particular to an access subsystem STA, by means of a user access interface Uu through which a data and voice signal TS is received and transmitted. This user access Uu interface, which has been referred to as an open interface so as to allow it to function in association with high quality terminals. The user terminal subsystem is made of a user identification module USIM, similar to the SIM card of the GSM standard, and the mobile equipment ME, i.e. the cellular phone, that communicates through appropriate interface equipment Cu;        access subsystem STA: this subsystem constitutes of the access network for the UMTS standard, the previously mentioned system UTRAN and connects to the transport network STT by means of a transport access Iu interface;        transport subsystem STT: said transport subsystem STT identified as “Core Network” in the UMTS standard constitutes the transport network of the UMTS system. Said subsystem STT, in addition to being connected by means of a transport access Iu interface to the access subsystem STA, must be able to interconnect with all the other existing networks (external networks, PSTN, ISDN, B-ISDN, Internet, etc.), which are identified in FIG. 1 by a block EXTNET. In this transport subsystem STT are comprised the information switching capabilities that are typical of cellular telephone systems. Namely, a Mobile Service Switching Center (MSC), a Home Location Register (HLR) database, a Visitor Location Center (VLR) database, an interconnection node or gateway GMSC, a node for the management of the packet switching SGSN Serving GPRS Support Node, and an interconnection node, or gateway, of the apparatus for packet switching GGSN (Gateway GPRS Support Node).        
In FIG. 1 it is shown, inside of the access subsystem STA, the base stations SNB that correspond to the base stations shown as Node-B in the UMTS standard. Namely, the radio stations disseminated through the territory of the mobile telephone system. Their principal function consists of exchanging, by means of the radio interface Uu, the data and voice signal TS with the user terminal subsystem STU. These base stations SNB also run the principal radio resources like, for example, the internal power control. Inside the access subsystem STA is comprised a radio network controller CRR as it is defined on the UMTS standard. This radio network controller CRR has complete control of all the radio resources in its domain. Namely, the base stations SNB connected to it by means of an appropriate controller station interface Iub.
The radio network controller CRR controls the working of one or more base stations SNB, controls the setting of radio channels (establishment and release connections), frequency hopping, internal handovers and other functions, communicating with the transport subsystem STT, in particular, with the switching center MSC. In large urban areas, there are a large number of base stations SNB controlled by a small number of radio network controllers CRR.
Each base station SNB is able to manage through the user/access interface Uu the connection to the network UNET of all the user subsystems STU that are located in the area surrounding the base station SNB; such an area, managed by one only base station SNB, is called cell. Base stations SNB are placed over the territory in a way to cover continuously the territory itself, minimizing the areas in which radio coverage is not sufficient. The aim is to allow the moving user subsystem STU to be connected continuously to the UNET network.
The user subsystem STU that are inside a certain cell exchange data bidirectionally with the base station SNB that identifies that cell: thus communication from user subsystem STU to base station SNB (Uplink transmission) and from base station SNB to user subsystem STU (downlink transmission) is obtained.
Due to the predictable rise in requests for multimedia information, the UNET network described in FIG. 1, must carry growing traffic from the external networks EXTNET to the transport/access interface Iu and access/user Uu in two directions.
As mentioned, to furnish a service qualitatively acceptable to the customers, the providers of UMTS type networks and wireless in general, will be forced to continue their investment in balancing network capacity with the increasing growth in demand.
In order to solve the above cited problem of increasing download data requirements, a telecommunication network has been disclosed by document EP 1 122 962 A, where several additional radio base stations provide additional monodirectional downlink channels. This solution has the problem of increasing electromagnetic pollution due to the irradiated electromagnetic power, and it does not solve the problem of the increasing consumption of the third generation terminals.